The UCSC graduate training program in Molecular, Cellular, and Developmental Biology provides intensive training in the skills necessary for outstanding research in modern biology. First year trainees undertake coursework emphasizing critical evaluation of scientific models, experimental approaches, and results, and they also participate in three ten-week laboratory rotations. Second-year students take an oral qualifying exam, and advanced students participate in a variety of seminars, advanced special topics courses, and research group meetings designed to provide continuing learning opportunities. The goal of the training program is, over a period of 5 to 6 years, to produce graduates who have a strong foundation in the specific area of their thesis research, as well as broad training and knowledge in molecular, cellular, and developmental biology. The program is administered by Advising and Admissions Committees according to policy guidelines stated in our Graduate Handbook and Faculty Guidelines. The training program is composed of 15 members of the Department of MCD Biology, and 10 affiliated faculty. The majority of the faculty is housed in the Sinsheimer Laboratories, with other faculty members scheduled to move to a new building being constructed adjacent to Sinsheimer Labs. The MCD training program provides an interactive and collaborative research environment for graduate training. Research in the training program utilizes a wide variety of approaches and model organisms, and is organized as clusters of faculty with shared interests, thereby creating critical masses of researchers to foster mutual support and scientific interaction. One such cluster, encompassed by the Center for the Molecular Biology of RNA, is internationally recognized for the study of RNA. The focus of the other research clusters include developmental biology, cell biology, structural biology, and gene expression. Students in the MCD Biology training program are therefore exposed to a wide range of different experimental problems and systems. During the first four years of NIH training support we have recruited and trained a number of students who would be amongst the best students in any training program. We are requesting a total of 8 predoctoral trainee positions in this renewal, which will be awarded to our best students.